I have heard one of my favorite self-image building stories from the student himself and I have repeated it in public to many teachers.
There was a fifteen-year-old student who was studying in a yeshiva in Jerusalem. The boy was bright, but he tended to be a bit dreamy. He didn't concentrate as well as he potentially could.
At the beginning of the school year he earned a fifty percent grade on a weekly test in Talmud. The teacher called him over, and the boy expected the teacher to reprimand him for not doing well.
Instead, the teacher said to him, "You received only a fifty because you only answered half the questions on the test. But let me show you how wonderfully you did. Look at what you answered for question number five. This was a difficult question and you answered it excellently! Look at what you answered to question number fourteen. You understood the intricacies of the entire section, and you explained yourself very clearly. Keep up the good work."
The boy felt good, but didn't change. The next week, the boy again received a fifty on the weekly Talmud test. The teacher called him over. The boy thought, "Now the teacher will really let me have it for not doing well."
To his surprise, the teacher said to him, "Your mark was only a fifty because you didn't answer all the questions on the test. But look at how well you answered the questions that you did answer. Look at question number six: Your answer shows a complete grasp of the material that this question asks. Look at question number nineteen. You explained the complex Tosafos with total clarity. Keep up the good work."
This time a major transformation occurred. The boy said to himself, "I see that I do have the ability to understand what we are learning in class. I need to focus better in class when the teacher is explaining the lesson. I also need to review what we learned a number of times. I believe that I have the ability to understand what we are learning in class."
The next week, the boy focused well during the actual class. The entire week he diligently reviewed the material that was covered in class. At the end of the week, when he received the results of the test, he had scored one hundred percent. He had answered every single question correctly. The same thing repeated itself with the next test, and the next test, and the next test. After four straight hundreds, his self-image was totally transformed.
He now realized, "I am someone who understands all that we learn when I concentrate and review."
That fellow is now married with a nice-sized family. He is considered a scholar by all who know him. When he first entered the large Mirrer Kollel, he received a perfect score on a difficult test.
How long did it take for that insightful and clever teacher to totally change the student's self-image? Just a couple of minutes, two weeks in a row.
(From Rabbi Zelig Pliskin's book: "Building Your Self- image and the Self-image of Others" (Artscroll) Chapter 7)